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Question
If (x - 9) : (3x + 6) is the duplicate ratio of 4 : 9, find the value of x.
Solution
As given (x - 9) : (3x + 6) is duplicate ratio of 4 : 9.
i.e., `(x - 9)/(3x + 6) = (4/9)^2`
`(x - 9)/(3x + 6) = (16)/(81)`
⇒ 81(x - 9) = 16(3x + 6)
81x - 729 = 48x + 96
81x - 48x = 96 + 729
33x = 825
x = `(825)/(33)`
= 25
Thus required value of x is 25.
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